CLAUDIA Karvan as a superhero? The small screen favourite is saving the day one case at a time as legal eagle Josephine Newton in the ABC's new comedy drama Newton's Law.

Fresh from producing Nine's hit new drama Doctor Doctor, Karvan is back in her first leading TV role since 2011's Spirited.

Dubbed the Upstairs Downstairs of legal dramas, Newton's Law follows Josephine as she juggles the high-powered barrister's world of Knox Chambers and the haphazard legal tangles of her former solicitor's office in the basement below.

"I loved the fact that Jospehine was a female role that was heroic and had authority, was unapologetic, resilient, warm, had a sense of humour. She's a bit of a superhero," Karvan tells News Regional Media's The Guide.

"You don't find female roles like that as much. I've had the privilege to play lots of wonderfully complex, well-written female roles but this one was unique in that she's aspirational and a fabulous role model.

"She understands what a privilege it is to help people, and what fuels her is this wonderful, fulfilling work. She gets an enormous amount of gratification from the work she's doing."

After more than a decade of battling to help the less fortunate, Josephine's suburban solicitor's practice is burnt down by a disgruntled, pyromaniac client.

The destruction, as well as a chance reunion with her law school buddy, Lewis Hughes (played by Black Sails star Toby Schmitz) prompts Josephine to join the prestigious Knox Chambers and takes on her first case in 15 years.

When she discovers a former car wash in the basement is up for lease, Newton's Legal is reincarnated as Chatterjee & Chatterjee Solicitors. Helena is reluctantly elevated to solicitor-in-charge and Josephine is free to pursue her new life upstairs - with her old life only a lift ride away.

Logie winner Miranda Tapsell also joins the Chatterjee team as investigator Skye Stewart.

"Miranda and Sean are one of the most hilarious duos I've seen on screen in a long time," Karvan says.

"They're like bickering siblings who are actually in love with each other. I think they'll be a really strong part of why people will want to watch the show."